Proliferative and secretory changes at the endometrial lining are the result of a complex intrauterine environment where sex steroid hormones and different local factors play an important role for endometrial thickening. Optimal endometrial thickness reflects an adequate maturation which is a key factor for embryo implantation. Here, we present a case of a woman with polycystic ovary who was treated using in vitro maturation (IVM) techniques. In addition, this patient showed a dyssynchrony between the endometrial phase characterised by endometrial thinning and the embryo development which had a negative impact for embryo implantation. A protocol using uterine perfusion of granulocyte colony-stimulating factor (G-CSF) was performed as an alternative treatment for the unresponsive endometrium. We found that uterine infusion of G-CSF quickly increased endometrial thickness resulting in a successful pregnancy and healthy born baby. These results suggest that G-CSF is a factor that participates during endometrial remodelling enhancing the synchronisation between uterine environment and embryo development.